Augmented air supply



Sept. 22, 1964 w. R. IRWIN AUGMENTED AIR SUPPLY 4 Sheets-Sheet 1 FiledApril 24, 1962 R E L O B TO IGNITION TRANSFORMER (NOT SHOWN) INVENTOR.

WILLIAM R. IRWIN S ept. 22, 1964 4 Sheets-Sheet 2 Filed April 24, 1962FIREBOX TO ELECTRIC RELAY TANK TO ELECTRIC RELAY INVENTOR. WILLIAM R.IRWIN Sept. 2.2, 1964" w. R. IRWIN AUGMENTED AIR SUPPLY 7 Filed April24, 1962 INVENTOR. WILLIAM R. IRWIN 4 Sheets-Sheet 3 TO POWER LINE T0POWER LINE T0 POWER LINE Sept. 22, 1964 w. R. IRWIN AUGMENTED AIR SUPPLYFiled April 24, 1962 CONDUIT 23b FUEL UNIT 4 Sheets-Sheet 4 INVENTOR.WILLIAM R. IRWIN United States Patent 3,149,662 AUGMENTED AIR SUPPLYWilliam R. Irwin, R0. Box 155, Blvd. Station,

Bronx 59, N.Y. Filed Apr. 24, 1962, Ser. No. 189,916 28 Claims. (Cl.158-28) This invention relates primarily to air supply means andsecondarily to use of such means whereby air at a plurality ofseparately defined rates is applied to support combustion of fuel at aplurality of separately defined rates.

The present application is a continuation in part of my priorapplication Serial No. 803,023, filed March 30, 1959, and now abandoned.

One of the objects of the invention is to provide novel arrangements ofa plurality of blowers or fans whereby air is supplied under pressure atone or more rates in accordance with the number of individual blowersemployed.

Another object is to provide means whereby an operating blower or fanmay be used to maintain ambient air at certain standards desired forcomfort.

Other objects and advantages will become apparent hereinafter.

In carrying out my invention in one form I provide a fuel burningapparatus comprising an oil burner, means for variably firing same andcontrol means applied to said firing means.

In carrying out my invention in another form I provide a fuel burningapparatus which differs from the aforesaid in some respects but whichillustrates how structure may be varied without departing from the maininventive concept.

In each apparatus a blower plurality is employed and in conjunctiontherewith means are provided to control the air intake rate and the airoutput rate of an associated individual blower or the air intake andoutput rates of an associated plurality of blowers.

In each apparatus a solenoid operated flow control valve is utilizedwhich directs fuel flow through a channel to an area where the rate offuel provided is synchronized with the proper rate of air necessary tosupport correct combustion of said fuel.

Air intake regulating means are provided for predetermination of thetime air is to be admitted to the intake side of an individual blowerand for the amount or rate of air that is to be admitted.

For a better understanding of the invention reference should be had tothe drawings in which:

FIG. 1 is a view, generally diagrammatic, of an embodiment of theinvention encompassing an oil burner. shown partly cut away, with an airsupply system, fuel supply system and an electrical control system;

FIG. 2 is a perspective view of an air intake louver operative by thenegative air pressure induced by a blower;

FIG. 3 is a diagrammatic view of another embodiment of an oil burningapparatus;

FIGS. 4, 5 and 6 are sectional views of part of a motorblower shaft withadjuncts, taken after previous inventions and with modifications imposedthereon, showing components at different stages of operation;

FIG. 7 is a diagrammatic view of a fuel unit comprising oil pumpingmeans, filter means, bypass means and pressure regulating means;

22 from where it would again be drawn to the pumping FIG. 8 is adiagrammatic, sectional view of an oil flow,

3,149,652 Patented Sept. 22., 1964 "ice with a compartment for two fans11 and 12 which are Welded together at a medianly situated closed plate13.

At said closed plate formed by the juncture of the fans, a flange 14 isformed peripherally thereon. The flange is endless and of exactly thesame diameter throughout and rotates in unison with the fans 11 and 12.

Throughout its circumference, the flange is enclosed by the slot 15 withvery small tolerance therebetween, the object of running the flangewithin the slot being to minimize the passage of air from one blower orfan to the other. This feature is not essential to the main concept andnumerous other methods are available for obtaining the same result.

A meter 16 when energized turns the fans 11 and 12 by means of the shaft17 which is supported on one side by the meter bearing 18 and on theother side by the outboard bearing 19. The meter 16 also providesrotation to the gears of a pumping means associated with oil pressureregulating means in a housing 20 and said rotation causes fuel oil to bedrawn from a tank 21 into the suction intake of said housing throughfuel suction conduit 22.

At this point it might be mentioned, that the embodiments wereillustrated diagrammatically for the most part, to show the effect thatone element would have on another, and, little effect was made to depictthe whole realistically, as with a working drawing. However, in practicethere would not be employed, except wih very heavy units of largecapacity, an outboard bearing, and, rather than having a pump, fuel oilstrainer, oil pressure regulating and oil flow cut-off means indispersed locations these components would in all probability beincorporated within a unitary device called a fuel unit, most of theelements of which are illustrated in another figure except for cut-offmeans which are depicted separately. To facilitate understanding, thehousing 21) should be considered as.-a fuel unit.

Fuel units have been in existence for some decades, are very compact andinexpensive, and regulate oil pressure and flow with great precision. Inpractice, fuel units are almost invariably mounted on a sidewall of theburner frame.

In FIG. 1 the ignition means have not been shown completely but they areindicated. In another figure means for lighting off the fuel areillustrated more comprehensively and it is believed that this willsufiice also for an understanding of the first embodiment.

Returning again to the description: The gears of the pumping means at 26when actuated, discharge oil drawn from the storage tank at a definedrate of pressure through conduit 23 and thence to a solenoid operated,flow regulating valve 24. Excess oil may be pumped back into the storagetank via conduit 9 when the structure 29 is considered to be a fuelunit. If said structure is viewed only as a pumping means, excess oilcan be returned to the oil supply tank 21 through conduit section 23a,the valve 25 serving as a pressure regulating valve, at which time thevalve 8 emplaced in oil conduit 9,'would be fully closed.

Preferably, and under ordinary circumstances, conduit 9 would be used toreturn excess oil to the suction conduit means, at which time valve 8would be opened andvalve 25 would be completely closed.

The solenoid operated, flow regulating valve 24 has one normally openedpassageway and one normally closed passageway therethrough. The normallyopened passageway leads to oil conduit 26 and calibrated nozzle 27 whilethe normally closed passageway when opened by effect of electricalenergy being applied to the coil 53 thereof, allows oil toflow toconduit 28 and calibrated nozzle 29. Opening of the normally closedpassageway of the valve results in the simultaneous closing of thenormally opened passageway.

Air to support the oil in combustion is indrawn through the louver bladecombinations 3t and 31, said combinations when in their opened positionsallowing ambient air to reach the suction sides of the blower means litand 12 respectively.

The louver blade combination 34 is of a type that immediately swings tothe opened position when motor 16 is energized and blower 11 generateson its suction side a pressure below atmospheric.

Louver blade combination 31, although similar in type to the bladecombination 30, is held in the closed position by latch 32 of theactuator 33 until the latch is withdrawn when said actuator iselectrically energized.

Upon withdrawal of the latch, the blade combination 31 opens inimmediate response to the negative air pressure generated by therotating vanes of the blower means. Air indrawn through either or bothof the louver blade combinations 3t} and 31 is discharged at a pressureabove atmospheric off the tips of the rotating vanes of the blower means11 and 12 respectively, into the blast tube 34 from whence it isdischarged into a firebox at a defined rate in synchronization with adefined rate of oil discharged from one or the other of the calibratednozzles 27 or 29.

Oil is sprayed from the nobbles in what is generally termed a solid orhollow cone form and most fuel oils discharged from a nozzle in suchmanner and intimately mixed with a proper rate of air are readilyignitable and combustible although some oils must to be preheated beforebeing introduced into a combustion chamber.

When a firebox of correctly balanced proportions is provided with adefined and correct quantity or rate of oil which is supported incombustion by an exact rate of air, the ultimate in efficiency isobtainable insofar as heat unit extraction from the fuel andavailability of said heat units for useful purposes may be concerned.

This object is attained with the present invention when the apparatus isemployed for the high flame condition. A high degree of efficiency mayalso be obtained when the apparatus is fired for the low flame conditionif the air used to support combustion for a smaller sized flame isrationed with exactitude.

In the drawing the latch 32 is shown as an enlongated component,pressable, in its normal, unactuated position, against the tops of thethree blades comprising the louver blade combination 31 to keep theblade plurality in the closed position. The individual blades arepivotally mounted and the upper portions of the blades extend outwardlyand their lower edges are pulled inward by negative air pressuregenerated by the blower means 12 when the wheel of said blower means isrotated upon motor 16 being energized. The said blades are held in theclosed position, as indicated, even though the wheel of the blower meansis rotating, until latch 32; is withdrawn from its holding position as aresult of the actuator 33 being electrically energized. Whilethe meansdepicted are effective, in actual practice more compact elements areavailable and would normally be used. In the construction shown, itwould suffice if latch 32 pressed against only one of the bladeplurality.

The burner and motor units are shown mounted on a base member 35. Aboiler is indicated in the drawing and responsive to pressures withinthe boiler and in con trol thereover are regulating means in the form ofmercury switches 36 and 37. A manually operative switch 38 makes orbreaks connection with L, shown as the line source of electricalpotential, and an electrical conduit section 39 extends between switch38 and mercury switch 36. Another conduit section 46 extends betweenswitch 36to an electrical junction 41 and extending between saidjunction and motor 16 is another conduit section 42. Another electricaljunction 43 is emplaced in section 42. and a conduit section 44 isconnected thereto which leads to the electrical transformer and ignition4- means which are indicated, but are not fully depicted in FIG. 1.

A conduit section 45 connects junction 41 with terminal #1 of relayswitchboard 46, said relay having a Nichrome type coil 47 which extendsbetween relay terminals #1 and #3. Terminal #3 has a connection leadingto ground which is similar to a connection to ground from the negativeside of the winding of motor 16.

Pivoted at terminal #1 of the relay switchboard is a contact blade 48which upon receiving heat generated by coil 4'? warps, after apredetermined interval, to make contact across terminals #1 and #2thereof. An electrical conduit section 49 extends between terminal #2and mercury switch 37 and another conduit section 50 extends from switch37 to a junction 51 and from last said junction a conduit section 52extends to the coil 53 of the solenoid'operated, flow control valve 24.From the ground side of coil 53 an electrical conduit section 54 extendsto a junction 55 from which a conduit section 56 leads to the groundterminal #3 of the relay switchboard. From junction Sll a conduitsection 56 leads to the coil of actuator 33 and from the negative sideof said coil a conduit section 57 extends to junction 55 which in turnis connected, as said, with conduit section 5%, terminal #3 and ground.

The louver blade combination 31 is shown more clearly in FIG. 2 and itshould be understood that said combination is similar to louver bladecombination 30 except that some elements of blade combination 31 havebeen transposed with regards to lateral position.

Various reference numbers indicating elements of combination 30 haveletters added thereto to distinguish same from members of the louverblade combination 31.

The three blades (1, b and c of combination 31 are pivotally mountedwithin a frame 58 with each of said blades having a beaded channel 59moulded thereon at a point well above the longitudinal median line andinto which one of the rods 60 is inserted, the rods being fixedlyemplaced in and through the side walls of said frame and intromittentthrough the cavities of said channels to allow blades a, b and c tofreely swing thereon.

levis type brackets 61 attached at their bases by rivets to thelowermost parts of said blades have positioned between their bifurcatearm portions, a rod 62, to which said bifurcate arms are attachedpivotally by clevis pins 63 at three equidistant points allowing for thevertical movement of said rod and the full closing of said blades toprevent entrance of outside air and, conversely, to provide a widedegree of are opening for said blades in order to allow the entry ofdesired quantities of outside air when it is required, each of theblades a, b and c of the combination, opening to the same degree whenactuated by negative air pressure generated by a blower.

The lower third of the rod 62 has threads 64 turned thereon to providemeans for an internally threaded nut 65 to be used for adjusting thedegree of opening of the louver blade plurality, the nut being turnedupwardly 'on said rod to decrease the permissive amount of opening thatsaid plurality will be allowed to accomplish or being turned downwardlyto increase the extent of louver opening, the nut making contact withthe underside of the base 35 when the blade plurality is drawn to theopened position by negative air pressure with the rod 62 passing withlimited tolerance through a hole drilled through said base.

In order to ensure that the louver blade plurality a, b and 0 may closesecurely by gravity a concavity 66 is formed on each blade with theconcavities of blades a and b matching the convex surfaces of the hollowchannels 59 of blades b and C respectively.

Operation'of the apparatus embodied in FIGS. 1 and 2 may be described asfollows:

With the manual switch 3% closed and the mercury switches 36 and 3? intheir closed positions due to lack of pressure within the boiler,electrical energy is'immcdiately transmitted through the closed mercuryswitch 36 to motor 16, to the transformer and ignition means connectedto conduit 44, to terminal #1 of relay 46 and to the Nichrome type coil47 connected between terminals #1 and #3 of said relay.

Upon motor 16 being energized it almost instantaneously reaches its fulloperational speed and rotates shaft 17, the blower wheel means 11 and 12and the gears of the pumping means in the casing at 20. Oil is drawnrespect to the rates of oil to be fired for combustion.

therein.

Oil in excess of that desired for combustion for a particular rate offiring is bypassed to the suction conduit 22, through conduit section 9,with valve 8 being fully opened at this time and valve fully closed. Ifoil is bypassed to the storage tank via conduit 23a, valve 25 would ofcourse be opened to the desired extent to maintain pressure in conduit23 at a predetermined rate while valve 8 would be in the closedposition. Under certain conditions valve 8 could be used as a secondarymeans for regulating oil pressure but this feature is not contemplatedin this disclosure.

Other methods of fuel regulation are possible but a brief description,included hereinafter, of how a fuel unit maintains oil flow at an exactrate and pressure, is believed ample for an understanding of this facet,insofar as it applies to the present concept.

Returning again to the description: When the motor 16 is energized thelouver blade combination is actuated to the predetermined extent of itsopened position by the negative air pressure generated by the rotatingelement of the blower means 11 as allowed by the setting of the nut 65aupon the threaded portion 64a of rod 62a, said rod being pulledvertically upwards by actuation of the louver blade combination and thenut making contact with the underside of base member at a fixed point onrod 62:: to provide a correct rate of air to support combustion of thefuel emitted from nozzle 27 for the low flame condition, the air beingdischarged under pressure from said blower through the blast tube 34 tothe beforementioned firebox. At this same time the blade of the blowermeans at 12 is also rotated at maximum, constant speed by the shaft 17but the louver combination 31 is effectively prevented from opening inresponse to induced air pressure generated by the rotation because ofthe application of latch 32 to the blades a, b and c of same, said latchbeing in application when actuator 33 is unenergized. This is thegeneral condition of startup of the apparatus following any period afterit has been completely shut down, and more particularly, it is betterknown as starting up under the low flame condition.

After a predetermined time interval the contact blade 48, in response toheatthrown off by the Nichrome type coil 47, completes its warpingmotion and makes connection across terminals #1 and #2 of relay 46. Acircuit is established and electrical energy is immediately transmittedfrom terminal #2 through the closed mercury switch 37 to coil 53 of thesolenoid operated, flow regulating valve 24 and to the louver actuator33.

The solenoid operated, flow regulating valve being actuated, thenormally opened passageway through same is closed while simultaneously,the normally closed passageway therethrough is opened. At this samemoment the actuator 33 is energized and the latch 32 thereof iswithdrawn from its holding position, allowing the louver bladecombination 31 to immediately respond to the negative air pressureinduced by the suction or vortex of the rotating blower element 12, saidlouver blade combination almost instantaneously swinging to its openedposition as permissively allowed by the setting of nut 65 upon thethreaded portion of rod 62.

Oil now flows through conduit 28 and the calibrated nozzle 29, and isemitted in a very fine spray therefrom. Oil discharged through nozzle 29is at a higher rate than when it is discharged through nozzle 27 and thecombined discharge air output of the blower elements 11 and 12 is at arate to correspond with that necessary for a minimum excess ofcombustion air in accordance with the oil discharge rate of nozzle 29,said rate being determined exactly, according to the size of thefirebox.

At this point it might be mentioned that various methods exist wherebythe solenoid operated, flow regulating valve 24 could be delayed in, orprevented from opening its normally closed passageway until it had beenascertained by use of orthodox, automatic means that the louver bladecombination 31 has been actuated to its opened position. Among themethods known are solenoid coil deceleration means to prevent theplunger of the solenoid valve from being actuated until said louverblade combination would have been opened and air supplied to the fireboxat the rate desired for the high flame condition, or, by the use of anair operated switch which would withhold energization from coil 53 ofsaid valve until it was automatically ascertained that the correct airrate had been provided.

After the high flame condition has been established it might bedesirable in some instances to have the apparatus continue thereunderuntil a boiler pressure of maximum limit were reached, whereat theentire apparatus would shut down due to the mercury switch 36 beingactuated by boiler steam pressure to its cut-out point.

Under such circumstance the function of the mercury switch 37 could beeliminated and the conduit bridged at this and other means used toassure a low flame startup. However, in most cases it would be desirableto have the apparatus start up under the low flame condition, go on tothe high flame condition after a short time interval and then, after adesired intermediate boiler pressure had been reached, return to the lowflame condition with no complete shut down of the appaaratus havingoccurred. Under this circumstance a boiler pressure could be maintainedwithin very narrow set limits.

Let us say, for example that mercury switch 36 has a cut-out point of 10psi. and a cut-in point of 9 psi. and all points below and that mercuryswitch 37 has a cut-out point of 8 psi. and a cut-in point of 7 psi. andall points below.

Following a complete shut down, and with the boiler cold, the apparatuswould re-start under the low flame condition and, after a certaininterval of time, say of thirty seconds, said apparatus would operateunder the high flame condition and would continue thus until an 8 p.s.i.boiler pressure was reached, whereat mercury switch 37 would be actuatedto its opened position. The solenoid operated flow regulating valve 24would then become deenergized simultaneously with actuator 33 and eachwould revert to its normal condition of operation, with the latch 32 ofthe actuator 33 closing the louver blade combination 31. The apparatuswould thus be restored to operation under the low flame condition.

Thereafter, according to the circumstances of operation including theactual rate of combustion for the low flame condition, the heatdissipation rate as related to whether the output of the system is usedfor comfort heating, a processing operation or the like, and variousother factors, the apparatus would either continue to build up boilerpressure, although at a greatly decelerated rate, to the cut-out pointof mercury switch 36 whereat it would be completely shut down, or, thesaid apparatus, would, under the low flame condition, cause the boilerpressure to be gradually diminished until the cutare-aces a in point of7 p.s.i. of mercury switch 37 was again realized whereby the systemwould again be caused to opcrate under the high fiame condition. Underthe last stated circumstance the steam pressure maintained would vary atmost by a one pound differential or between 7 and 8 psi.

The operating condition last described other than continuallymaintaining the steam pressure within very narrow limits with beneficialresults to be derived thereby insofar as processing is concerned, alsoconserves heat and fuel; provides a greater amount of useful heat peramount of fuel used, saves the wear and tear caused by constantrecycling of the equipment, avoids the irregularities involved in suchrecycling with consequent derogatory results in the product produced andthe necessary frequent replacement of parts such as refractories,relays, motors, boiler surfaces and other appurtenances destroyedrapidly by excessive contraction and expansion caused by wide variationsin temperature when the apparatus makes numerous complete stops duringthe course of the working day.

The embodiment of FIG. 3 is a variation of the invention wherein an oilburner 7t) is shown which has two air discharge tubes 71 and '72 both ofwhich feed air into a blast tube '73 which leads to a firebox.

A motor 74 has a shaft '75 extending outwardly from both ends and saidshaft provides rotative power for a pump '76, a primary blower means 7'7and an auxiliary blower means 78. The shaft has adjustably positionedtherearound an air intake plate 79 for manual adjustment of the rate ofincoming air to the suction side of the primary blower and a system ofair intake louvers 80 for the auxiliary blower which open by centrifugalforces if allowed to do so by an actuator 81 which is responsive toelectrical control means.

The primary air intake louver plate has an adjusting screw 82 byivhichthe plate 79 is set to allow a fixed rate of air to enter the suctionside of the primary blower means.

Various types of louver means other than the centrifugally orpneumatically operated, could be employed for either blower means, ascould other types of actuator rather than the electrically responsivetype used herein to achieve the intended result.

Air intake rate adjustment for the louvers 8t) of the auxiliary blowermeans is predetermined by the manually fixed setting of the arm 83.

Oil is drawn from the storage tank, indicated but not shown in thedrawing, to the suction intake of the pump 76 through conduit 84 and isdischarged from the pump under pressure through conduit 85 to a solenoidoperated, fiow regulating valve 86 which is similar to the solenoidoperated valve 24 previously described.

With the motor 74 running but without the solenoid valve 86 beingelectrically actuated, the oil discharged from the pump passes throughthe normally opened passageway of the valve into the oil conduit 557 andthence through the regulating valve 38 and into and through the nozzleline 859 to be emitted from the nozzle ?t as a fine spray.

As the regulating valve 38 is preset to pass a low rate of oiltherethrough to be emitted into the firebox the rate of air necessary toproperly support combustion of said low rate of oil is supplied insuflicient and exact degree with a minimum of excess by the primaryblower means 77.

The air discharged by the blower means 77 passes through the air duct 72and blast tube '73 and is blown into the firebox as the oil is emittedthereinto from the nozzle 9%. This constitutes the operation for the lowflame condition. At this time the centrifugally operable louvers 8th ofthe auxiliary blower are held in the closed position by the plunger ofthe unenergized actuator 81.

.When the high flame condition is called for by a thermostat, aquastator other suitable instrument, the solenoid operated valve 86 isenergized and the normally opened passageway thereof is closed while itsnormally closed passa eway is simultaneously opened. Oil is thenpropelled by the pump 76 through the normally closed, but now openedpassageway of the valve 86 and into and through conduit 91, through theregulating valve 92, which is adjusted to pass oil at a higher rate thanis regulating valve 88, and thence into nozzle 99 from which it isemitted as a fine spray.

The actuator 81 is energized simultaneously with the solenoid operatedvalve 86 and the louver combination 15 i) is immediately opened to thefull, preset extent through the centrifugal forces imposed by theenergization of the motor 74 and rotation of shaft 75.

When the louver combination 86 is opened, air is indrawn into the eye orsuction side of the blower means 78 and is discharged off the tips ofthe blower wheel under pressure into and through duct 71, thence intothe blast tube 7.) where it is intermixed with air from blower 77,augmenting same and being discharged therewith from tube 73 into thefirebox to provide an exact rate of air to support combustion of the oilemitted into the firebox at the high rate. It is almost needless to saythat the high rate of fuel with the high rate of air to supportcombustion thereof is calculated according to the exact dimensions ofthe firebox to achieve the most efficient rate of combustion therein.

The transformer 93, changes line voltage and current to high voltage,low current electricity and high tension cables 94 carry this energy tometal igniters 95 to cause an intense electric spark to occur across theair gap of the igniter plurality. Porcelain sleeves cover all parts ofthe igniters except their forward ends to avoid short circuiting of thehigh voltage electricity to other parts of the burner complex. Thetransformer was omitted from the drawing in FIG. 1 but the transformerand ignition means to be used with that embodiment could be similar tothose used in the embodiment of FIG. 3.

A bypass conduit 97 on the pump discharge side causes oil in excess ofthe rate required for firing to be returned to conduit 34. A regulatingvalve $3 is placed in said bypass conduit to provide means for precisecontrol of oil pressure as oil is delivered to the nozzle.

Because the embodiments of FIGS. 1 and 3 are depicted diagrammatically,it was thought necessary to provide more definitive illustrations andexplanations of louvers operatively responsive to applied centrifugalforce means and, oil pressure regulating means, whereby oil may bemaintained for firing purposes under pressures where variations are sominute that to all intents and purposes they are unnoticeable.

The centrifugally operated louver means depicted in FTGS. 4, 5 and 6 aretaken after means well known in the art. The shaft 12% has a push rod Pworking in an axial socket and when centrifugal force is generatedthrough rotation of the shaft a crosspiece N pushes forward in through alongitudinal diametric slot cut in the shaft at 0 against the rod P.

The outer end of the rod P bears against an arm of a bell-crank lever Qthrough which the application of force is continued in order to actuatelouvers or valves to uncover the air intake openings.

For convenience to the description, said push rod P has been dividedinto two separated sections 121 and 122 and said sections have beenenclosed within a strong, compressible spring 123 which is slidable inthe hollow section of the shaft.

One end of the said spring is positioned against a lug 124 formed onsection 121 of said rod and the other end of the spring is positionedagainst a stop 125 formed on the rod section 122.

Positioned against the arm of the bell-crank Q is the plunger 1126 of anelectrically operable actuator 127.

in PEG. 4 the components of shaft are shown in 9 the normal orunactua-ted position, there being no application of centrifugal force.

In FIG. the components are depicted under the application of centrifugalforce but with the air intake louvers being unable to be actuatedbecause plunger 126 of actuator 127 is in its normal holding positionagainst the outermost end of section 122 of the push rod P. Theinnermost rod section 121 is however forced towards the outer rodsection 122 against the counter pressure exerted by the spring 123,through centrifugal forces exerted on the crosspiece N.

In FIG. 6 the components are depicted as being under the application ofcentrifugal forces with the air intake louvers now having been freed toopen by withdrawal of plunger 126 through energization of actuator 127.It will be noted that the inner rod section 121 of push rod P is in thesame position in FIG. 6 as it was shown in FIG. 5 but the compression ofthe spring 123 in FIG. 5 is released in FIG. 6, with the compressiveforce of the spring transmitted instead to rod section 122 because ofthe plunger 126 having been withdrawn, therefor allowing said rodsection 122 to move outwardly and absorbing the thrust of the springthereby.

Referring to FIG. 7, the previously mentioned, diagrammaticrepresentation of a fuel unit is included in the draw ings because suchuni-ts are almost universally used as components of burners of thegeneral type shown in FIGS. 1 and 3.

While many varieties of fuel unit exist it is thought that the unitschematically depicted in FIG. 7 is a fair representation of the manyavailable.

As was previously remarked, the average fuel unit is very compact, hasonly one shaft means and is usually positioned because of its small sizeupon a sidewall of the burner frame.

In the drawing the suction conduit 9.2a extends between the oil storagetank (not shown) to a strainer element 140, positioned almost invariablyon the intake or low pressure side of the fuel unit. From the strainerthe oil is drawn through conduit 141 to the first stage or, the suctiongear stage 142 of the pumping component, and from said first stage theoil is discharged through a conduit 143 into a so-called bypass bodyelement 144 by the gears of said suction stage wherefrom it may leave byone of two exit ports, one of said ports 145 leading to passageway 146which connects to the entrance port 147 of a second stage or dischargegear stage 148 of the pumping component. oil is discharged underpressure from said stage via a passageway 149 and into an element 150,said efement having incorporated therein various constituents of apressure regulating means, the oil entering the element at chamber 151wherein it is subjected to regulation of pressure by a needle valve 152in association with a piston 153 having an orifice port 154 and anorifice passageway 155 drilled in and therethrough.

The piston is movably positioned within element 151) and is freelyslidable therein despite very close tolerance between itself and thepiston confining means of said element. A spring 156 is emplaced tooppose movement of the piston with one end of said spring havingcontinuous contact with the upper surface of the piston and the otherend having continuous contact with a plate 157. An adjusting screw 158is placed in contact with said plate and said screw extends through thetop exterior surface 159 of said element. The screw upon being turnedinwardly against the plate causes greater compression of the spring 156with resultant greater pressure of the oil delivered to the dischargeoil conduit 23b.

The tip 160 of the needle valve is in vibrating contact with the orificeport 154 of the channel drilled through said piston and upon afluctuation of oil pressure in chamber 151 said vibrating contactbetween the orifice .and needle valve tip is varied accordingly tomaintain a precise rate of pressure of the oil discharged to conduit 23bwhich, in the embodiment of FIG. 1, would corre- 'spond to conduit 23 orin the embodiment of FIG. 3, would correspond to conduit 85.

Excess oil determined in extent by the pressure maintained in thechamber 151 by the setting of pressure regulating adjustment screw 158,travels through the channel of the piston to the upper part of theinterior of the element 150 and is propelled therefrom into passageway161, from which it is discharged into the bypass component from which itis either returned to the oil storage tank via conduit 23a which wouldcorrespond to conduit 23:: in the embodiment of FIG. 1 or, if conduit 9of the embodiment of FIG. 1 were in use to return excess oil to suctionconduit 22, then conduit 23a of the embodiment of FIG. 7 wouldcorrespond to said conduit 9. If the fuel unit of FIG. 7 were to replacepump 76 of the embodiment of FIG. 3 the bypassed oil would be returnedto the suction conduit 34 depicted in the last said figure.

While it is manifest that numerous alterations could be made in theconstruction of the fuel unit proper, such as by changing the piston fora diaphragm, adding additional springs, shunting the bypassed oil to thestrainer element or to the first stage gears rather than to the element144, by using only a single stage of pumping gears, or additionally, byincorporating oil flow, cut-off means within the fuel unit as would bedone in the usual case, it is believed nevertheless that the descriptionand the illustration accompanying same is sufiicient to identify thecorrect nature of this precision instrument for maintaining exactpressures of fuel oil for combustion purposes.

In FIG. 8, oil cut-off means are shown positioned in an oil dischargeline to a calibrated nozzle, illustrating schematically how after dripof oil from a nozzle may be prevented from occuring after rotation ofthe pumping gear means has ceased. It is evident that the device couldbe greatly improved and the drawing of same is included in the figuresonly to give a general idea of its purpose.

The body of the oil cut-off component 17%, may be considered asconnected to any of the oil conduits heretofore mentioned, orillustrated in FIGS. 1, 3 and 7. An oil passage 171 extends withincomponent from a said discharge conduit to an interior wall 172 thereof.A pressure plate 173 is slidable with very close tolerance within achamber 174 formed within the component and said plate is part of aunitary piece which incorporates a valve element 175 and a valve stem176. A permanently positioned pressure plate 177 has a cavity 173 formedtherein in which the end of said valve stem is slidable. A spring 179which is compressible at about 50 pounds p.s.i. encircles the valve stemwith one end of said spring in engagement with the fixed plate 177 andthe other end in engagement with the slidable plate 173.

An oil passageway 180 is drilled through the body of the component at181, and said passageway is in communication with a calibrated nozzle132, screwed to the anterior part thereof. When oil under pressure fromthe rotating gears of a pump oil passes through a said of thestemsliding in cavity 178 of plate 177. Under this circumstance the oildischarged from the pumping means flows through passageway 180 to thecalibrated nozzle 182 from which it is emitted as a fine spray.Immediately upon cessation of pressure applied to the oil, the

spring with its expansive force of 50 p.s.i. closes off the passageway181) by forcing the valve element 175 against same, thus preventing oildripping from the nozzle.

Oil drip'from the nozzle is known in the trade as after drip and for agreat many years many types and variations of types of oil cut-oil meanshave been avai able and the type diagrammatically illustrated is butindicative of the general purpose and application of same.

What I claim is:

1. A high flame, low flame oil burning system comprising two fans havingunitary shaft means, air discharge duct means common to both fans,separate air intake means for each fan, said air intake means closingwhen said fans are at rest, automatic holding means applicable to theair intake means of one fan, releasing means for said holding means, theseparate air intake means for one fan opening by negative air pressurewhen both fans are rotated unitarily and the separate air intake meansfor the other fan remaining closed by said holding means being appliedthereto, a high rate of air supply occurring when said two fans arerotated unitarily on said shaft means and the separate air intake meansfor each fan is opened, a low rate of air supply occuring when said twofans are rotated unitarily on said shaft means and the separate airintake means for one fan is opened and the eparate air intake means forthe other fan is closed, electric motor means applicable to said shaftmeans, an oil supply source, oil pumping means actuable by said electricmotor and said shaft means, oil pressure regulating means associatedwith said pumping eans, oil conduit means extending from said oil supplysource to the suction intake of said pumping means, an oil conduit meansextending from the discharge outlet of said pumping means for thedelivery of oil under pressure therefrom, solenoid operated iiowregulating valve means in last said oil conduit means, said regulatingvalve means comprising inlet passageway means for fuel oil, a pluralityof outlet passageway means and closure means for each of said outletpassageways, electrically actuable operating means for said closuremeans, means mechanically interconnecting each of said closure means forsimultaneous operation thereof, said closure means being associated withsaid outlet passageways to effect the opening of one passageway uponclosure of another, oil discharge conduit means extend ng from each ofthe said plurality of outlet passageway means of said regulating valvemeans, oil ilow metering means in each of last said oil dischargeconduit means, a first electrical control means individual to saidelectric motor, a second electrical control means common to said flowregulating valve means and said releasing means, said first electricalcontrol means being responsive individually to a call for the low flamecondition to energize said electric motor, and said first electricalcontrol means and said second electrical control means beingconcurrently responsive to a call for the high flame condition, saidfirst control means electrically actuating said electric motor and saidsecond control means electrically actuating said closure means of saidflow regulating valve means and electrically actuating said releasingmeans to effect the release of said air intake holding means.

2. A high flame, low flame oil burning system comprising two fans havingunitary shaft means, air discharge means individual to each fan, airdischarge duct means common to both fans, separate air intake means foreach fan, said a r intake means closing when said fans are at rest,automatic holding means applicable to the air intake means or" one fan,releasing means for said holding means, the separate air intake meansfor one fan opening by negative air pressure when both fans are rotatedunitarily and the separate air intake means for the other fan remainingclosed by said holding means being applied thereto, said separate airintakemeans for the last said fan opening automatically when saidholding means are not applied, a high rate of air supply occuring whensaid two fans are rotated unitarily on said shaft means and the separateair intake means for each fan are opened, the low rate of air supplyoccuring when said two fans are rotated unitarily on said shaft meansand the separate air intake means for one fan'are opened and theseparate air intake means for the other fan are closed, electric motormeans applicable to said shaft means, an oil supply source, oil pumpingmeans actuable by said electric motor and shaft means, oil pressureregulating means associated with said pumping means, oil conduit meansextending from said oil supply source to the suction intake of saidpumping means, oil conduit means extending from the discharge outlet ofsaid pump for the delivery of oil under pressure therefrom, solenoidoperated flow regulating valve means in last said conduit means, saidsolenoid operated flow regulating valve means comprising inletpassageway means for fuel oil, a plurality of outlet passageways,closure means for each of said outlet passageways, electrically actuableoperatin means for said closure means, means mechanicallyinterconnecting each of said closure means for the simultaneousoperation thereof, said closure means being associated with said outletpassageways to elfect the opening of one passageway upon closure ofanother, oil discharge conduit means extending from each of the saidplurality of outlet passageways of said re ulating valve means, oil flowmetering means in each of last said oil discharge conduit means, a firstelectrical control means individual to said electric motor, a secondelectrical control means common to said solenoid operated flowregulating valve means and said releasing means, said first electricalcontrol means being responsive individually to requirement for the lowflame condition to energize said electric motor, and said firstelectrical control means and said second electricfl control means beingconcurrently responsive to a requirement for the high flame condition,said first control means electrically actuating said electric motor andsaid second control means electrically actuating said closure means ofsaid solenoid operated flow regulating valve means and electricallyactuating said releasing means to effect the release of said air intakeholding means.

3. A high flame, low flame oil burning system comprising two fans havingunitary shaft means, air discharge duct means common to both fans,separate air intake means for each fan, said air intake means closingwhen said fans are at rest, automatic holding means applicable to theair intake means of one fan, releasing means for said holding means, theseparate air intake means for one fan opening when both fans are rotatedunitarily and the separate air intake means for the other fan remainingclosed by said holding means being applied thereto, said separate airintake means for the last said fan opening when said holding means arenot applied, a high rate of air supply occurring when said two fans arerotated unitarily on said shaft means and the separate air intake meansfor each fan is opened, a low rate of air supply occurring when said twofans are rotated unitarily on said shaft means and the separate airintake means for one fan is opened and the separate air intake means forthe other fan is closed, electric motor means applicable to said shaftmeans, an oil supply source, oil pumping means actuable by said electricmotor and said shaft means, oil pressure regulating means associatedwith said pumping means, oil conduit means extending from said oilsupply source to the suction intake of said pumping means, oil conduitmeans extending from the discharge outlet of said pumping means for thedelivery of oil under pressure therefrom, flow regulating valve means inlast said conduit means comprising inlet means for fuel oil, apluralityof outlet passageways and closure means for each of saidoutletpassageways, electrically actuable operating means for saidclosure means, means mechanically interconnecting each of said closuremeans for simultaneous operation thereof, said closure means beingassociated with said outlet passageways to eifect the opening of onepassageway upon closure of another, oil discharge conduit meansextending from each ofthe said plurality of outlet passageways of I 13said regulating valve means, oil flow metering means in each of said oildischarge conduit means, a first electrical control means individual tosaid electric motor, a

'second electrical control means common to said flow regulating valvemeans and said releasing means, said first electrical control meansbeing responsive individ ually to a requirement for the low flamecondition to energize said electric motor, and said first electricalcontrol means and said second electrical control means beingconcurrently responsive to a requirement for the high flame condition,said first control means electrically actuating said electric motor andsaid second control means electrically actuating said closure means ofsaid flow regulating Valve means and electrically actuating saidreleasing means to effect the release of said air intake holding means.

4. A system according to claim 3 including means re sponsive tocentrifugal forces for opening the separate air intake means for eachfan.

5. A system according to claim 3 including means responsive tocentrifugal forces for opening the separate air intake means for a fanand with holding means applicable to said air intake means wherebycentrifugal application of force may take place without effect foropening said air intake means until the application of said holdingmeans is released.

prising two fans having unitary shaft means, air discharge duct meanscommon to both fans, normally closed, separate air intake means for eachfan, said air intake means closing when said fans come to rest, holdingmeans for the separate air intake means of one fan, releasing means forsaid holding means, the separate air intake means for one fan openingwhen both fans are rotated unitarily and the separate air intake meansfor the other fan remaining closed because of said holding means beingapplied thereto, said separate air intake means for the last said fanopening when said holding means are not applied, a high volume of airdelivered when said two fans are rotated unitarily on said shaft meansand the separate air intake means for each fan is opened, a low volumeof air delivered when said two fans are rotated unitarily on said shaftmeans and the separate air intake means for one fan is opened and theseparate air intake means for the other fan is closed, an electric motorapplicable to said shaft means, an oil supply source, oil pumping meansactuable by said electric motor and said shaft means, oil pressureregulating means associated with said pumping means, oil conduit meansextending from said oil supply source to the suction intake of saidpumping means, oil conduit means extending from said pumping means forthe delivery of oil under pressure therefrom, flow regulating valvemeans connected to last said conduit means comprising inlet means forfuel oil, a plurality of outlet means and closure means for each of saidoutlet means, electrically actuable operating means for said closuremeans, said closure means being associated with said outlet means toeffect the opening of one of said outlet means upon closure of another,oil

discharge conduit means extending from each of the said plurality ofoutlet means of said regulating valve means, oil flow metering means ineach of last said discharge conduit means, a first electrical controlmeans individual to said electric motor, a second electrical controlmeans common to said flo-w regulating valve means and said releasingmeans, said first electrical control means being responsive individuallyto a requirement for the low flame condition to energize said electricmotor, and said first electrical control means and said secondelectrical control means being concurrently responsive to a requirementfor the high flame condition, said first control means electricallyactuating said electric motor and said second control means electricallyactuating said closure means of 'said flow regulating valve means andelectrically actuat- 14 ing said releasing to effect the release of saidair intake holding means.

7. A system according to claim 6 including means responsive tocentrifugal forces for opening the separate air intake means for eachfan.

8. A system according to claim 6 including means responsive tocentrifugal forces for opening the separate air intake means for a fanand with holding means applicable to said air intake means wherebycentrifugal application of force may take place without effect foropening said air intake means until the application of said holdingmeans is released.

9. A high volume, low volume air delivery system comprising a blowerelement plurality having unitary shaft means, automatic turning meansfor rotating said shaft means, air discharge duct means common to saidblower element plurality, a first, separate, air intake means associatedwith a first blower element of said plurality, a

second, separate, air intake means associated with a second blowerelement of said plurality, each of said air intake means operable toopen by the negative air pressure induced by the rotation of itsrespective, associated, blower element, each of said first air intakemeans and said second air intake means operable to close by gravityforces when the associated blower elements thereof come to rest,automatic holding means to prevent the opening of said first air intakemeans in response to the negative air pressure induced by itsassociated, rotating, blower element, automatic releasing means for saidholding means, the high volume air delivery condition occuring when saidblower element plurality is rotating on said shaft means and said firstand said second air intake means are opened and said holding means arereleased from application by said releasing means, and the low volumeair delivery condition occurring when said blower element plurality isrotating on said shaft means and said first, separate, air intake meansassociated with said first blower element is held in the closed positionby said holding means to counteract the negative air pressure induced bysaid first blower element, said holding means not being released by saidreleasing means.

10. A high volume, low volume air delivery system comprising a blowerelement plurality having unitary shaft means, automatic turning meansfor rotating said shaft means, air discharge duct means common to saidblower element plurality, a first, separate, air intake means associatedwith a first blower element of said plurality, a second, separate, airintake means associated with a second blower element of said plurality,each of said air intake means operable to open automatically when saidautomatic turning means are actuated, each of said air intake meansoperable to close automatically upon the cessation of actuation of saidautomatic turning means, automatic holding means to prevent the openingof said first air intake means when said automatic turning means areactu ated, automatic releasing means for said holding means, the highvolume air delivery condition occurring when said blower elementplurality is rotating on said shaft means and said first and said secondair intake means are opened and said holding means are released fromapplication by said releasing means, and the low volume air deliverycondition occurringwhen said blower element plurality is rotating onsaid shaft means and said first, separate, air intake means associatedwith said first blower element is held in the closed position by saidholding means to prevent said first, separate air intake means fromopening automatically, said holding means not being released by saidreleasing means. I

11. A high volume, low volume air delivery system comprising a blowerelement plurality having unitary shaft means, electric motor means forrotating said shaft means, air discharge means individual to each blowerelement, a first, separate, air intake means associated with a firstblower element of said plurality, a second, separate, air intake means"associated with a second blower element of said plurality, each of saidair intake means operable to open automatically when said shaft meansare rotated by said electric motor means, each of said air intake meansoperable to close automatically upon the cessation of r0- tation of saidshaft means by said electric motor means, automatic holding means toprevent the opening of said first air intake means when said shaft meansare rotated by said electric motor means, automatic releasing means forsaid holding means, the high volume air delivery condition occurringwhen said blower element plurality is rotated on said shaft means bysaid electric motor means and said first and said second air intakemeans are opened and said holding means are released from application bysaid releasing means, and the low volume air delivery conditionoccurring when said blower element plurality is rotated on said shaftmeans by said electric motor means and said first, separate, air intakemeans associated with said first blower element is held in the closedposition to prevent said first, separate, air intake means from openingautomatically, said holding means not being released by said releasingmeans.

12. A high volume, low volume air delivery system comprising a blowerelement plurality having unitary shaft means, electric motor means forrotating said shaft means, air discharge means individual to each blowerelement, a first, separate, normally closed, air intake means associatedwith a first blower element of said plurality, a second, separate, airintake means associated with a second blower element of said plurality,said first air intake means operable to open automatically uponrequirement for the high volume air delivery condition, automaticholding means applicable to said first air intake means upon requirementfor the low volume air delivery condition, releasing means for saidholding means, the high volume air delivery condition occurring whensaid blower element plurality is rotated on said shaft means by saidelectric motor means and said first and said second air intake means areopened and said holding means are released from application by saidreleasing means, and said low volume air delivery condition occurringwhen said blower element plurality is rotated on said shaft means bysaid electric motor means and said second, separate, air intake meansare open and said first, separate, air intake means are held closed bysaid automatic holding means applied thereto.

13. A system as defined in claim 11 in which the automatic opening ofsaid air intake means is caused by the actuation of centrifugal forcesgenerated by the rotation of said shaft means by said electric blowermeans.

14. A system as defined in claim ll including separating means forpreventing any substantial quantity of discharge air frcm one blowerelement entering the air intake side of the other blower element.

15. A system as defined in claim 12 including separating means forpreventing any substantial quantity of discharge air from one blowerelement entering the air intake side of the other blower element.

16. An air delivery system comprising a blower element plurality havingunitary shaft means, discharge means individual to each blower element,normally closed air intake means individual to each blower element, saidair intake means of each blower element operable to open automaticallywhen its associated blower element is rotated on said sha't means,automatic holding means applicable to the air intake means associatedwith a said blower element, releasing mcans for said holding means,

and means for the automatic rotation of said shaft means.

17. An air delivery system comprising a blower element plurality havincunitary shaft means, air discharge means individual to each blowerelement, normally closed air intake means individual to each blower elemom, said air intake means of each blower element operable to openautomatically whenits associated blower element is rotated on said shaftmeans, automatic holding means applicableto the air intake meansassociated with l6 a number less than the total of said blower clementplurality, releasing means for said holding means, and mea is for theautomatic rotation of said shaft means.

18. An air delivery system comprising a blower element plurality havingunitary shaft means, air discharge means individual to each blowerelement, normally closed air intake means individual to each blowerelement, said air intake means of each blower element operable to openby the centrifugal forces generated by the rotation of said shaft means,automatic holding means applicable to the air intake means associatedwith a number less than the total of said blower element plurality,automatic releasing means for said holding means, and means for theautomatic rotation of said shaft means.

19. An air delivery system comprising a blower element plurality havingunitary shaft means, air discharge means individual to each blowerelement, air discharge means common to the blower element plurality,normally closed air intake means associated with a number less than thetotal of said blower element plurality, said normally closed air intakemeans operable to open automatically upon the rotation of said shaftmeans, automatic holding means applicable to said normally closed airintake means to prevent the opening of same upon the rotation of saidshaft means, automatic releasing means for said holding means, andelectric motor means for the automatic rotation of said shaft means.

20. A high flame, low flame fuel burning system comprising a blowerelement plurality having unitary shaft means, an electric motor forrotating said shaft means, air discharge duct means common to the blowerelement plurality, a first, separate, normally closed air intake meansassociated with a first blower element of said plurality, a second,separate, air intake means associated with a second blower element ofsaid plurality, each of said air intake means being open when arequirement is made for the high flame condition, automatic holdingmeans applicable to the first air intake means, releasing m ans for saidholding means, said first air intake means operable to be held in theclosed position by said holding means when a requirement is made for thelow flame condition upon a start-up of the fuel burning system oroperable to be closed from the opened position by said holding meanswhen a requirement is made for said system to revert to the low fiamecondition from the high flame condition, fuel metering meanssynchronized with said blower element plurality whereby a high rate offuel is delivered concurrently with a high rate of air and a low rate offuel is delivered concurrently with a low rate of air, a first controlmeans individual to said electric motor, a second control means commonto said releasing means and said fuel metering means, said first controlmeans being responsive individually to a requirement for too low flamecondition to cause the electrical energization of said electric motor,and said fi st control means and said second control means beingconcurrently esponsive to a requirement for the high flame condition,

said first control means to cause the energization of said electricmotor and said second control means to cause the actuation of saidreleasing means and said fuel metering means and thereby effectingrelease of said holding means from said first air intake means.

21. A system as defined in claim 20 in which said fuel metering meanscomprise valve means embracing a plurality of passageways wherethroughprior to actuation a lesser rate of fuel may flow and subsequent toactuation a greater rate of fuel may flow.

22. A system as defined in claim 20 in which said first, separate,normally closed air intake means are operable to be opened by thegeneration of centrifugal forces upon the electrical energization ofsaid electric motor md the rotation thereby of said shaft means whensaid holding means are not in application.

23. A system as defined in claim 20 in which said fuel metering meanscomprise a solenoid operated, fiow regulating valve means having asingle body, with a normally opened passageway therethrough and anormally closed passageway therethrough and closure means for each ofsaid passageways, means mechanically interconnecting each of saidclosure means for the simultaneous operation thereof to effect theopening of one passageway upon the closure of another and calibrationmeans in association with each of said passageways whereby onepassageway, when opened, allows the flow therethrough of a greater rateof fuel, and the other passageway, when opened, allows the flowtherethrough of a lesser rate of fuel.

24. A high flame, low flame fuel burning system comprising a blowerelement plurality having unitary shaft means, an electric motor forrotating said shaft means, air discharge means individual to each blowerelement, a first, separate, normally closed air intake means associatedwith a first blower element of said plurality, a second, separate, airintake means associated with a second blower element of said plurality,each of said air intake means being open when a requirement is made forthe high flame condition, automatic holding means applicable to thefirst air intake means, releasing means for said holding means, saidfirst air intake means operable to be held in the closed position bysaid holding means when a requirement is made for the low flamecondition upon a start-up of the fuel burning system or operable to beclosed from the opened position by said holding means when a requirementis made for said system to revert to the low flame condition from thehigh flame condition, fuel metering means synchronized with said blowerelement plurality whereby a high rate of fuel is delivered concurrentlywith a high rate of air and a low rate of fuel is delivered concurrentlywith a low rate of air, a first control means individual to saidelectric motor, a second control means common to said releasing meansand said fuel metering means, said first control means being responsiveindividually to a requirement for the low flame condition to cause theelectrical energization of said electric motor, and said first controlmeans and said second control means being concurrently responsive to arequirement for the high flame condition, said first control means tocause the energization of said electric motor and said second controlmeans to cause the actuation of said releasing means and said fuelmetering means and thereby effecting release of said holding means fromsaid first air effecting release of said holding means from said firstair intake means.

25. A system as defined in claim 24 in which said fuel metering meanscomprise valve means embracing a plurality of passageways wherethroughprior to actuation a lesser rate of fuel may flow and subsequent toactuation a greater rate of fuel may flow.

26. A system as defined in claim 24 in which said fuel metering meanscomprise a solenoid operated, flow regulating valve means, having asingle body, with a normally opened passageway therethrough and-anormally closed passageway therethrough and closure means for each ofsaid passageways, means mechanically interconnecting each of saidclosure means for the simultaneous operation thereof to effect theopening of one passageway upon the closure of another and calibrationmeans in association with each of said passageways whereby onepassageway, when opened, allows the flow therethrough of a greater rateof fuel, and the other passageway, when opened, allows the flowtherethrough of a lesser rate of fuel.

27. A system as defined in claim 24 having separating means forpreventing any substantial quantity of discharge air from one blowerelement entering the intake air side of the other blower element.

28. A system as defined in claim 20 including separating means forpreventing any substantial quantity of discharge air from one blowerelement entering the intake air side of the other blower element.

References Cited in the file of this patent UNITED STATES PATENTS1,637,820 Hawkins Aug. 2, 1927 1,648,796 Albrecht Nov. 8, 1927 1,741,529Marion Dec. 31, 1929 1,760,166 Page May 27, 1930 1,846,863 Hagen Feb.23, 1932 2,937,697 Johnston May 24, 1960 FOREIGN PATENTS 85,914 DenmarkJune 21, 1958

1. A HIGH FLAME, LOW FLAME OIL BURNING SYSTEM COMPRISING TWO FANS HAVINGUNITARY SHAFT MEANS, AIR DISCHARGE DUCT MEANS COMMON TO BOTH FANS,SEPARATE AIR INTAKE MEANS FOR EACH FAN, SAID AIR INTAKE MEANS CLOSINGWHEN SAID FANS ARE AT REST, AUTOMATIC HOLDING MEANS APPLICABLE TO THEAIR INTAKE MEANS OF ONE FAN, RELEASING MEANS FOR SAID HOLDING MEANS, THESEPARATE AIR INTAKE MEANS FOR ONE FAN OPENING BY NEGATIVE AIR PRESSUREWHEN BOTH FANS ARE ROTATED UNITARILY AND THE SEPARATE AIR INTAKE MEANSFOR THE OTHER FAN REMAINING CLOSED BY SAID HOLDING MEANS BEING APPLIEDTHERETO, A HIGH RATE OF AIR SUPPLY OCCURRING WHEN SAID TWO FANS AREROTATED UNITARILY ON SAID SHAFT MEANS AND THE SEPARATE AIR INTAKE MEANSFOR EACH FAN IS OPENED, A LOW RATE OF AIR SUPPLY OCCURING WHEN SAID TWOFANS ARE ROTATED UNITARILY ON SAID SHAFT MEANS AND THE SEPARATE AIRINTAKE MEANS FOR ONE FAN IS OPENED AND THE SEPARATE AIR INTAKE MEANS FORTHE OTHER FAN IS CLOSED, ELECTRIC MOTOR MEANS APPLICABLE TO SAID SHAFTMEANS, AN OIL SUPPLY SOURCE, OIL PUMPING MEANS ACTUABLE BY SAID ELECTRICMOTOR AND SAID SHAFT MEANS, OIL PRESSURE REGULATING MEANS ASSOCIATEDWITH SAID PUMPING MEANS, OIL CONDUIT MEANS EXTENDING FROM SAID OILSUPPLY SOURCE TO THE SUCTION INTAKE OF SAID PUMPING MEANS, AN OILCONDUIT MEANS EXTENDING FROM THE DISCHARGE OUTLET OF SAID PUMPING MEANSFOR THE DELIVERY OF OIL UNDER PRESSURE THEREFROM, SOLENOID OPERATED FLOWREGULATING VALVE MEANS IN LAST SAID OIL CONDUIT MEANS, SAID REGULATINGVALVE MEANS COMPRISING INLET PASSAGEWAY MEANS FOR FUEL OIL, A PLURALITYOF OUTLET PASSAGEWAY MEANS AND CLOSURE MEANS FOR EACH OF SAID OUTLETPASSAGEWAYS, ELECTRICALLY ACTUABLE OPERATING MEANS FOR SAID CLOSUREMEANS, MEANS MECHANICALLY INTERCONNECTING EACH OF SAID CLOSURE MEANS FORSIMULTANEOUS OPERATION THEREOF, SAID CLOSURE MEANS BEING ASSOCIATED WITHSAID OUTLET PASSAGEWAYS TO EFFECT THE OPENING OF ONE PASSAGEWAY UPONCLOSURE OF ANOTHER, OIL DISCHARGE CONDUIT MEANS EXTENDING FROM EACH OFTHE SAID PLURALITY OF OUTLET PASSAGEWAY MEANS OF SAID REGULATING VALVEMEANS, OIL FLOW METERING MEANS IN EACH OF LAST SAID OIL DISCHARGECONDUIT MEANS, A FIRST ELECTRICAL CONTROL MEANS INDIVIDUAL TO SAIDELECTRIC MOTOR, A SECOND ELECTRICAL CONTROL MEANS COMMON TO SAID FLOWREGULATING VALVE MEANS AND SAID RELEASING MEANS, SAID FIRST ELECTRICALCONTROL MEANS BEING RESPONSIVE INDIVIDUALLY TO A CALL FOR THE LOW FLAMECONDITION TO ENERGIZE SAID ELECTRIC MOTOR, AND SAID FIRST ELECTRICALCONTROL MEANS AND SAID SECOND ELECTRICAL CONTROL MEANS BEINGCONCURRENTLY RESPONSIVE TO A CALL FOR THE HIGH FLAME CONDITION, SAIDFIRST CONTROL MEANS ELECTRICALLY ACTUATING SAID ELECTRIC MOTOR AND SAIDSECOND CONTROL MEANS ELECTRICALLY ACTUATING SAID CLOSURE MEANS OF SAIDFLOW REGULATING VALVE MEANS AND ELECTRICALLY ACTUATING SAID RELEASINGMEANS TO EFFECT THE RELEASE OF SAID AIR INTAKE HOLDING MEANS.
 9. A HIGHVOLUME, LOW VOLUME AIR DELIVERY SYSTEM COMPRISING A BLOWER ELEMENTPLURALITY HAVING UNITARY SHAFT MEANS, AUTOMATIC TURNING MEANS FORROTATING SAID SHAFT MEANS, AIR DISCHARGE DUCT MEANS COMMON TO SAIDBLOWER ELEMENT PLURALITY, A FIRST, SEPARATE, AIR INTAKE MEANS ASSOCIATEDWITH A FIRST BLOWER ELEMENT OF SAID PLURALITY, A SECOND, SEPARATE, AIRINTAKE MEANS ASSOCIATED WITH A SECOND BLOWER ELEMENT OF SAID PLURALITY,EACH OF SAID AIR INTAKE MEANS OPERABLE TO OPEN BY THE NEGATIVE AIRPRESSURE INDUCED BY THE ROTATION OF ITS RESPECTIVE, ASSOCIATED, BLOWERELEMENT, EACH OF SAID FIRST AIR INTAKE MEANS AND SAID SECOND AIR INTAKEMEANS OPERABLE TO CLOSE BY GRAVITY FORCES WHEN THE ASSOCIATED BLOWERELEMENTS THEREOF COME TO REST, AUTOMATIC HOLDING MEANS TO PREVENT THEOPENING OF SAID FIRST AIR INTAKE MEANS IN RESPONSE TO THE NEGATIVE AIRPRESSURE INDUCED BY ITS ASSOCIATED, ROTATING, BLOWER ELEMENT, AUTOMATICRELEASING MEANS FOR SAID HOLDING MEANS, THE HIGH VOLUME AIR DELIVERYCONDITION OCCURING WHEN SAID BLOWER ELEMENT PLURALITY IS ROTATING ONSAID SHAFT MEANS AND SAID FIRST AND SAID SECOND AIR INTAKE MEANS AREOPENED AND SAID HOLDING MEANS ARE RELEASED FROM APPLICATION BY SAIDRELEASING MEANS, AND THE LOW VOLUME AIR DELIVERY CONDITION OCCURRINGWHEN SAID BLOWER ELEMENT PLURALITY IS ROTATING ON SAID SHAFT MEANS ANDSAID FIRST, SEPARATE, AIR INTAKE MEANS ASSOCIATED WITH SAID FIRST BLOWERELEMENT IS HELD IN THE CLOSED POSITION BY SAID HOLDING MEANS TOCOUNTERACT THE NEGATIVE AIR PRESSURE INDUCED BY SAID FIRST BLOWERELEMENT, SAID HOLDING MEANS NOT BEING RELEASED BY SAID RELEASING MEANS.